Efficiently determining the size and physical characteristics of relatively small particles (such as cells or microbubbles) can be a challenging task. In particular, gas-filled microbubbles with an encapsulating shell, generally referred to as ultrasound contrast agents (UCAs), are used regularly in diagnostic ultrasound and are becoming important in therapeutic ultrasound applications. In general, UCAs are very small bubbles, on the order of a micron in diameter, stabilized against dissolution with a coating material (such as a lipid-based material, an albumin-based material, or a polymer-based material). Clearly, the physical properties of any material used for medical applications must be well understood. As such, it would be desirable to provide efficient techniques for investigating the physical properties of UCAs, to enable UCAs to be more effectively used in diagnostic and therapeutic medical applications.
Further, it would thus be desirable if such techniques could be used to efficiently study other types of similar sized particles.